Self-cleaning spray nozzle



1952 A. H. BAHNSON, JR 2,613,992

SELF CLEANING SPRAY NOZZLE Filed Nov. 5, 1948 Patented Oct. 14, 1952UNITED STATES PATENT OFFICE 2,613,992 v I I SELF-CLEANING SPRAY NOZZLEAgnew lLBahnson, Jr., Winston-Salem, N. C.

Application November 5, 1948, Serial No. 58,475

4 Claims.

1 This invention relates to .nozzles for creating a mist or a more orless finely divided spray of water or other liquid delivered underpressure for use particularly in washing or humidifying air.

One of the principal problems encountered with these nozzles is theclogging of one or more of the many small apertures, through which theliquid is passed in forming the spray, by small particles of dirt orother foreign matter that may and usually are entrained with the liquid.Filter screens have been proposed for trapping these particles but thesehave not proven entirely satisfactory. If the screen mesh is made fineenough to adequately stop all foreign matter, it causes too great a dropin nozzle pressure, and if made coarse enough so as to not materiallyaffect the nozzle pressure, the interstices in the mesh are too large toblock the particles. Then too, the filters must be removed and cleanedperiodically and this adds to the maintenance cost.

It has also been proposed to use cleaners of the automatic type, builtinto the nozzle, and

which perform a cleaning operation each time that the nozzle is turnedon, or off, depending upon the construction, but these are not suitablefor spray nozzles of the type in which the apertures are distributedaround and extend substantially laterally from a barrel typedistribution head.

The general object of this invention is to provide 'an improvedself-contained type of nozzle cleaner for multi-apertured nozzles of theabove-described type and which operates automatically each time thenozzle is put into operation thus eliminating the necessity fordisassembling and reassembling the nozzle each time that cleaningbecomes necessary, and also assuring a continuous, high quality spray.

Another object is to provide a cleaner unit for spray nozzles having aminimum of parts and which is simple and inexpensive to manufacture andservice.

The foregoing as Well as other objects and advantages inherent in theimproved construction will become more apparent from the vfollowingdetailed description of a preferred form of the invention and from theaccompanying drawings in which Fig. 1 is a longitudinal central sectionthrough the improved nozzle;

Fig. 2 is an end elevation looking towards the left in Fig. 1;

Fig. 3 is a transverse section taken on line 33 of Fi 1, and

Fig. *4 is a view in perspective of the piston used to clear the nozzleapertures.

Referring now to the drawings, the nozzle is seen to be comprised of acylindrical metal barrel, one end of which is threaded at 2 forattachment to a pipe, not shown, through which the liquid is deliveredto the nozzle. To establish-a fine spray efiect, a, plurality of smalldiameter apertures .3 extending through the barrel are used, and theseare arranged in sets of two each around the circumference of the barrel.in two axially spaced rows. The generally laterally extending aperturesof each set are preferably arranged at a converging angle such that therespective streams of liquid flowing therethrough will impinge upon eachother at a point .iairly close to the exterior surface of the barrel Ithus breaking up the streams into a mist of very fine liquid particles.The walls of the apertures 3 are also .seen to possess a taper divergentin the direction of flow for a purpose that will be later explained.

.In addition to the two main circumferential arrays of sets of aperture'3, the nozzle barrel ,1 is also provided with a pair of apertures 4 atthe end opposite the threaded end 2. These apertures are likewise set atan angle to each other and deliver a generally diverging conical mistcentering about the extended longitudinal axis of the barrel I. Forconvenience in manufacture, the apertures 4 are formed in a central plug5 stemmed at .6 to facilitate removal and which is threaded into a plug1 of larger diameter that is in turn threaded into the end of the barrell. The head 8 of plug .1 is given ,a hexagonal or some other polygonalshape for receiving a wrench, as is also the barrel l at 9, and containsan axial aperture lll spaced from the confronting end wall of plug 6 topermit passage of the liquid discharged through the set of end apertures4.

In accordance with the present invention, the improved, automaticallyoperating cleaning device for the main group of nozzle apertures 3 iscomprised of a piston H located within the barrel 1 and which worksagainst a coil spring 12. The right end of spring 12 as viewed in Fig. 1extends into a well portion it of reduced diameter in the barrel forsupporting and maintaining the several turns of the spring in axialalignment as it expands and is compressed, while the left end of thespring is seated in an annular groove 14 in the end face l5 of piston H.

Piston II is reduced in diameter intermediate its ends thus establishinga central portion I6 of reduced diameter and end flanges I1 and I8 thediameters of which are substantially the same as but slightly less thanthe internal diameter of the barrel I so as to permit a close slidingfit between the piston flanges and the barrel wall. Also the left endflange I! is seen to contain a plurality of axially extending openingsI9 to permit free flow of the liquid therethrough. Finally to keeppiston II and spring I2 in place and establish a starting position forthe piston, a retaining sleeve 20 is used. This sleeve is inserted inthe left end of the barrel and is provided with an external stopshoulder 2I adapted to abut against the end face of the nozzle barrel.

Operation of the cleaning device is as follows:

With the nozzle cut off from the pressure liquid, piston II and springI2 occupy respectively the positions shown in full lines in Fig. 1.When, however, the liquid is introduced into the nozzle body I at theleft end, the pressure of the same acting principally against theimperforate piston flang I8 forces piston II to the right. During thismovement, the piston end flanges l1 and I8 in sliding past the entranceedges of the apertures 3 shear off or agitate loose any dirt or otherforeign matter that may have lodged at the entrances to one or more ofthe apertures and the normal pressure of the liquid is thus suflicientto force the foreign matter out through the apertures. The latterbecause of their divergent taper provide free passage of the particlesand this serves to prevent reclogging the apertures proper.

Piston II stops when it reaches the position shown in broken lines withspring I2 fully compressed and the piston end flange I8 to the right ofthe row of apertures 3 nearest the right end. The main portion of theliquid thus flows freely through all of the apertures 3. A minor portionof the liquid, however, escapes past end flange I8 between the rim ofthe latter and the wall of the barrel and enters the end apertures 4 toform the auxiliary end spray. While the amount of liquid flowing throughapertures 4 constitutes but a minor portion of the total supplied, itsrate of flow is nevertheless sufficient to maintain a reduced pressurecondition on that side of the piston flange I8 nearest the end apertures4 with the result that piston I I will be maintained in the positionshown in broken lines so long as the pressure behind the liquid ismaintained. However, when the pressure is turned off, the restoringforce built up within spring I2 due to its compression is now free toexert itself and thus pushes piston I I back to its initial positionshown in full lines. Piston I I obviously executes a second clearingaction of the entrance edges of the apertures 3 during the returnstroke.

Normally a single stroke of piston I I is all that is needed to cleanout any foreign matter which may have accumulated. However, if aparticularly bad clogging condition arises, the cleaning cycle may ofcourse be repeated as many times as necessary merely by turning theliquid pressure on and oil.

In conclusion, it is to be understood that while the illustratedconstruction is to be preferred, various modifications thereof may occurto and possibly be preferred by others who may seek to practice theinvention but without, however, departing from the spirit and scope ofthe invention as defined in the appended claims. Thus, for example, ifin certain applications an end spray is not considered advantageous orindeed should become undesirable, the set of end orifices 4 may bedispensed with and an air bleed substituted therefor to prevent acounterpressure from being built up on the end of piston I I opposite tothat of the liquid pressure as the piston moves to the right. In such acase the imperforate piston end flange I8 would be modified so as topresent a closer fit with the wall of barrel I, a packing ring beingused if necessary, to prevent an of the liquid from leaking past thepiston to the air bleed side.

Having now fully described my invention and illustrated a preferredconstructional embodiment of the same, I claim:

1. A self-cleaning spray nozzle comprising a cylindrical barrel having afluid inlet at one end thereof adapted to be connected to a source offluid under pressure and a plurality of apertures spaced longitudinallyalong and extending outwardly through the barrel wall in a generallylateral direction, a piston slidable within said barrel having adiameter substantially equal to the internal diameter of said barrel soas to wipe across the inlet edges of said apertures, a helical loadingspring in said barrel for said piston, one end of said spring beingfixed and the other end thereof being engaged with one face of thepiston and biasing the latter to a starting position at the fluid inletend of said barrel, a removable sleeve disposed within said barrel atthe fluid inlet end thereto, the end face of said sleeve within saidbarrel constituting a stop for said piston and establishing the saidstarting position for the piston, the opposite face of said piston whenin said starting position being subject to pressure from the fluid whenadmitted to said inlet, and causing said piston to be driven from itsstarting position along said barrel past said apertures and to compresssaid loading spring.

2. A self-cleaning spray nozzle as defined in claim 1 wherein theopposite end of said sleeve includes a shoulder abutting the end face ofsaid barrel.

3. A self-cleaning spray nozzle comprising a cylindrical barrel having afluid inlet at one end thereof adapted to be connected to a source offluid under pressure and a plurality of apertures spaced longitudinallyalong and extending outwardly through the barrel wall in a generallylateral direction and a well portion at the other end of said barrelprovided with an aperture extending from the base of the well portionthrough the end wall of the barrel in a direction generallylongitudinally of the barrel, a piston slidable within said barrelhaving a, diameter substantially equal to the internal diameter of saidbarrel so as to wipe across the inlet edges of said laterally extendingapertures, a helical loading spring in said barrel for said piston, oneend of said spring being received in said well and the other end of saidspring being engaged with one end face of said piston and biasing thepiston to a starting position at the fluid inlet end of said barrel, the

opposite end face of said piston when in starting position being subjectto pressure from the fluid when admitted to said inlet and causing saidpiston to be driven from its starting position along said barrel pastsaid laterally extending apertures and to compress said loading spring.

4. A self-cleaning spray nozzle as defined in claim 3 wherein theportion of said piston intermediate its ends is of reduced diameter toestablish end flanges and the end flange adjacent the I 6 v fluid inletto said barrel is apertured axially, the Number Name Date other endflange being imperforate. 1,180,807 Vedder Apr. 25, 1916 AGNEW H.BAHNSON, JR. 1,416,401 Dudley May 16, 1922 1,762,313 Snow et a1 June 10,1930 REFERENCES CITED 5 1,879,012 Armstrong Sebt. 27, 1932 The followingreferences are of record in the 2,096,307 Hulberb Q 1937 file of thispatent: -gg Foster O 3. 322

2, 43, Latter Mar. 1 UNITED STATES PATENTS 2,466,182 Peeps Apr. 5, 1949Number Name Date 10 405,015 Crance June 11, 1889

